FIG. 1 illustrates a conventional memory assembly 10. The memory assembly 10 has a memory board unit 20 that stands on a mother board 11 and is connected to the mother board 11 with a connector device 30. The memory assembly 10 also has a crossbar chip device 40 that is flip-chip mounted onto the mother board 11. The memory board unit 20 has memory boards 22 that are arranged on a daughter board 23 and are connected to the daughter board 23 with a connector device 24. Each of the memory boards 22 has memories 21 mounted on a circuit board. The lower end of the daughter board 23 stands on the mother board 11 and is connected to the mother board 11 with the connector device 30. The memory boards 22 horizontally protrude from the daughter board 23. The crossbar chip device 40 is located below the memory boards 22.
The memory assembly 10 has a width of W and a height of H. Hereinafter, W will be used as a unit width, and H will be used as a unit height.
FIG. 2 illustrates a memory assembly 10A that is a conventional example having an increased memory capacity. The memory assembly 10A is formed by adding another memory board unit 20 to the memory assembly 10 shown in FIG. 1.
This memory assembly 10A has a width of 2×W, which is twice as wide as the conventional memory assembly 10 having the width of W. With such a structure, it is necessary to increase the depth of each multiprocessor device, and it is difficult to put such a multiprocessor device on the market.
FIG. 3 illustrates a memory assembly 10B that is another conventional example having an increased memory capacity. The memory assembly 10B includes a memory board unit 20B. This memory board unit 20B has a daughter board 23B that is 1.5 times as tall as the daughter board 23 shown in FIG. 1. Memory boards 22 are mounted to the daughter board 23B. The number of memory boards 22 mounted to the daughter board 22B is twice as large as the number of memory boards 22 contained in the memory assembly 10 shown in FIG. 1.
The memory assembly 10B maintains the width of W.
As the number of memory boards 22 mounted to the daughter board 22B is doubled, a connector device 30B needs to have an increased number of terminals. A ready-made connector cannot serve as the connector device 30B, and a specially designed connector needs to be prepared. As a result, the production cost of the memory assembly 10B increases.